Intermediate compressor case for gas turbine engines

ABSTRACT

In a multistage split compressor wherein the low pressure compressor has a plurality of stages on one rotor and the high pressure compressor has a plurality of stages on another rotor, the low pressure compressor is removable as a unit from the high pressure compressor by making the intermediate case in two pieces, one integral with the low pressure compressor case with an associated bearing for the low pressure rotor and the other integral with the high pressure compressor case also with an associated bearing for the high pressure rotor. By having these two pieces removably secured together, the associated compressor cases may be separated by removal of the attachment devices holding the cases together, and each case carries with it the associated bearing for the enclosed rotor.

United States Patent Monsarrat Sept. 23, 1975 l l INTERMEDIATE COMPRESSOR CASE FOR GAS TURBINE ENGINES William G. Monsarrat, South Windsor, Conn.

[75] Inventor:

[73] Assignee: United Technologies Corporation, Hartford Conn.

22 Filed; Feb. 7, 1974 [21] Appl.N0r:440,407

2.880.574 4/[959 Howald 60/39.3l

Primar E.t'aminerC. J. Husar Assistant E.\'aminer-L. .l. Casoregola Attorney. Agent, or Firm-Charles A. Warren ABSTRACT In a multistage split compressor wherein the low pressure compressor has a plurality of stages on one rotor and the high pressure compressor has a plurality of stages on another rotor. the low pressure compressor is removable as a unit from the high pressure compressor by making the intermediate casein two pieces. one integral with the low pressure compressor case with an associated bearing for the low pressure rotor and the other integral with the high pressure compressor case also with an associated bearing for the high pressure rotor. By having these two pieces removably secured together, the associated compressor cases may be separated by removal of the attachment devices holding the cases together, and each case carries with it the associated bearing for the enclosed rotor.

6 Claims, 1 Drawing Figure INTERMEDIATE COMPRESSOR CASE FOR GAS TURBINE ENGINES BAOKGROUND OF THE INVENTION In the development of high performance split multistage compressors and the associated split turbines. it has become more and more desirable to build the entire engine in components that may be assembled or disassembled as complete entities. For example. the low pressure compressor including the casing with stator vanes therein, and the enclosed rotor with vanes thereon may be positioned as a unit in the engine or replaced as a unit in the engine if it could be readily connected to the remainder of the engine with the rotor held in position within the surrounding casing. To do so, the component needs to have the rotor adequately supported within the surrounding casing to prevent damage to the blading.

STATEMENT OF THE INVENTION component is essentially an integral part of the high pressure casing and the part of the intermediate case associated with the low pressure component is essentially a part of. the low pressure casing with the two parts oi the case attached to one another by releasable attachment means accessible externally of the case.

Other features and advantages will be apparent from the specification and claims and from the accompanying drawings which illustrate an embodiment of the in vention.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE is a sectional view of the inter mediate case and associated parts of the high and low compressor components.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The invention is in general adapted for use in a multistage compressor inwhich the low pressure stages are on a rotor independent of the high pressure stages and the low and high pressure rotors are separately driven trosn separately driven turbine stages. Such a construction is well known as in the Satin US. Pat. No. 1.747567. As above stated it is desirable to remove cithtr compressor component as an assembled unit from the remainder of the power plant without disassembly of the component. thereby facilitating initial assembly of the power plant. or replacement of either compo dent in the event of failure within the component such s a loss of blades or vanes in any one of thc comprcsso: stagesv Rclcrring to the drain ing the low pressure comprcs- \UI' component includes a casing 2 hanng a plurality of ions of macs 4 positioned therein and these rows ol writes illCl lldIC with rows of blades not shown on the low pressure rotor 8. The rotor 8 is supported within the casing by a bearing not shown at the inlet end and a bearing 10 at the outlet end The detailed construction ofthe low pressure component is conventional and the rotor is hollow to permit insertion of a tool. not shown, from the inlet end. The alternating rows of vanes and blades define a gas path through the low pressure casing and gas is discharged from the low pres sure compressor into the high pressure compressor component through an intermediate case 12.

The high pressure compressor is also generally con ventional construction have a plurality of rows of vanes 14, only one being shown. positioned within a casing 16 and these rows of vanes alternate with rows of blades I8, only one row being shown on a rotor 20. The latter is supported at the inlet end by a bearing 22 and at its outlet end by a bearing, not shown. The present invention is concerned with the construction of the intermediate case 12 and the support of the bearings 10 and 22 therein to provide for assembly and disassembly of the two components as entities. The support of the bearing at the inlet end of the low pressure compressor and the construction of the bearing at the outlet end of the high pressure compressor may be conventional as for example in the Savin patent above described.

To accomplish the purpose of the present invention, the intermediate case consists of two rings or sleeves 24 and 26 extending toward and into contact with each other from the low pressure casing and the high pressure casing respectively. These two sleeves define the outer wall of the gas path through the intermediate cas ing from the low pressure compressor stages to the high pressure compressor stagesv These rings are in alignment with one another and are substantially the same diameter. Case 2 is bolted to ring 24 by bolts 25 and case 16 is held to ring 26 by bolts 27. For the purpose of this invention the rings 24 and 26 are essentially intc= grill with the low and high pressure casings respectively.

Each ring has a row of struts 28 and 30 respectively that support at their inner ends rings 32 and 34 forming the inner wall of the gas path through the intermediate case The rings 32 and 34 are in alignment with one another and in spaced relation to the outer rings The ring 24, struts 28 and inner ring 32 carry a bearing support 34 for bearing 10 for the low pressure rotor as shown. The ring 26, struts 30 and inner ring 34 carry an independent bearing support 36 for hearing 22 for the high pressure rotorv Thus. the two bearings are indepen dcntly supported within the two part intermediate case.

The two slcmcs 24 and 26 have cooperating outwardly extending flanges 38 and 40 at their abutting ends which are secured together by a row of bolts 42 l'or attachment oi the components together. The inner rings 32 and 34 hate u cooperating piloting groove 42 and flange 44 to hold the components in concentric re Lition \1 hilt: thc tliingcs arc bolted together or unbolted l'or disusscmbl In a construction of this t \pc the low pressure rotor is attached to a shaft that extends through the high pressure rotor and that must lie disconnected for rclHU\Ltl of the loo pressure component from the engine. lo this catcnt. the tlriic shut't 4o f-llllll] the high pressure rotor i 1-pliiicrl at 48 to the \ltmc 50 extending from and forming a. port oi the low pressure rotor 3. and which is jlTLllliltltlt ll .ht hearing Ill. The shalt 46 Is threaded ;it the cod and engaged bx l threaded ring 52 which engages a shoulder 54 on the low pressure rotor. The ring 52 has tool engaging notches 56 at the end through the use of these notches may be turned by a tool not shown inserted through the low pressure rotor from the inlet end with devices thereon to engage in said notches 56.

The details of the bearing construction at the other ends of the low pressure and high pressure components are not shown as these are generally conventional in construction. It will be noted that when the row of bolts 42 are removed and the low pressure component is removed from the engine the low pressure rotor will be supported securely within the low pressure casing by the end bearings including the bearing 10 so that the vanes and blades will not be damaged. Similarly, the assembled low pressure casing and rotor as a component may be reassembled to the high pressure component as a unit for the rotor of each unit supported by its associated bearing in the casing so that the rotors are in alignment with one another and so that no damage is done to the rotors or casings when the components are placed in assembled relation to one another.

It should be understood that the invention is not limited to the particular embodiments shown and described herein, but that various changes and modifications may be made without departing from the spirit or scope of this novel concept as defined by the following claims.

Having thus described typical embodiments of my invention, that which I claim as new and desire to secure by Letters Patent of the United States is:

1. An intermediate case for a split compressor in which a low pressure compressor component having a rotor and surrounding Casing discharges gas through the intermediate case to a high pressure compressor component also having a casing surrounding a rotor in alignment with the low pressure rotor, said intermediate case including:

cooperating outer rings on the adjacent ends of the low pressure and high pressure casings extending toward and into engagement with one another, said rings being in alignment and defining the outer wall of the gas path through the intermediate case, and

said rings having flanges on the abutting ends for attachment of the casings and said rings together,

releasable attachment means holding said flanges together,

each ring having struts extending inwardly across the gas path,

each set of struts engaging and supporting an inner ring, the inner rings being in alignment and defining the inner wall of the gas path, and

a bearing support carried by each inner ring and supported from the respective easing by the associated outer ring, the attached struts and the associated inner ring, each bearing support having a bearing for the associated rotor.

2. An intermediate case as in claim 1 in which one pair of said aligned rings has cooperating guide elements for establishing concentricity of the components in assembly.

3. In a multistage compressor:

a high pressure unit including a high pressure rotor and a surrounding high pressure stator, the latter having at its inlet end a plurality of struts extending across the gas path a bearing support extending inwardly from said struts and carried thereby and a bearing carried by said support, the adjacent end of the rotor being supported by said bearing,

a low pressure unit including a low pressure rotor and a surrounding low pressure stator, said low pressure unit discharging compressed air into the high pressure unit, said low pressure stator having at its discharge end a plurality of inwardly extending support struts positioned across the air path a bearing support extending inwardly from said struts and carried thereby, and a separate bearing carried by said support in spaced relation to and in alignment with the bearing carried by the high pressure rotor, the low pressure rotor being supported in said separate bearing,

attachment flanges on the adjacent ends of said high pressure stator and low pressure stator and releasable securing means holding said attachment means together.

4. ln a split compressor construction a low pressure compressor including a rotor having blades thereon and a surrounding casing having stator vanes cooperating with the blades,

a high pressure compressor in alignment with the low pressure compressor and receiving compressed gas therefrom, said high pressure compressor including a rotor having blades and a surrounding casing having stator vanes therein cooperating with the blades,

each of said casings having a cooperating outer sleeve projecting therefrom, said sleeves extending toward and into contact with each other and lo cated at the outlet end of the low pressure compressor and the inlet end of the high pressure compressor respectively,

releasable attachment means securing said sleeves together,

each outer sleeve having supporting struts extending inwardly across the gas path and a cooperating inner sleeve at the inner ends of the struts, a bearing mounting extending inwardly from each inner sleeve and each mounting supporting a bearing therein with the hearings in alignment, the bearing carried by the high pressure sleeve supporting the adjacent end of the high pressure rotor, and the bearing carried by the low pressure sleeve supporting the adjacent end of the low pressure rotor.

5. A split compressor construction as in claim 4 in which the low pressure rotor is hollow and has a projecting drive shaft attached thereto extending through the high pressure rotor and means accessible through the hollow rotor for disengaging the rotor from the shaft.

6.'A split compressor construction as in claim 4 in which the sleeves have cooperating attachment flanges at their adjacent ends with the flanges secured together by a releasable holding element whereby the low pressure compressor may be removed as an entity by the removal of said elements, with the rotor supported within the surrounding casing by the bearing associated with the low pressure sleeve. 

1. An intermediate case for a split compressor in which a low pressure compressor component having a rotor and surrounding casing discharges gas through the intermediate case to a high pressure compressor component also having a casing surrounding a rotor in alignment with the low pressure rotor, said intermediate case including: cooperating outer rings on the adjacent ends of the low pressure and high pressure casings extending toward and into engagement with one another, said rings being in alignment and defining the outer wall of the gas path through the intermediate case, and said rings having flanges on the abutting ends for attachment of the casings and said rings together, releasable attachment means holding said flanges together, each ring having struts extending inwardly across the gas path, each set of struts engaging and supporting an inner ring, the inner rings being in alignment and defining the inner wall of the gas path, and a bearing support carried by each inner ring and supported from the respective casing by the associated outer ring, the attached struts and the associated inner ring, each bearing support having a bearing for the associated rotor.
 2. An intermediate case as in claim 1 in which one pair of said aligned rings has cooperating guide elements for establishing concentricity of the components in assembly.
 3. In a multistage compressor: a high pressure unit including a high pressure rotor and a surrounding high pressure stator, the latter having at its inlet end a plurality of struts extending across the gas path a bearing support extending inwardly from said struts and carried thereby and a bearing carried by said support, the adjacent end of the rotor being supported by said bearing, a low pressure unit including a low pressure rotor and a surrounding low pressure stator, said low pressure unit discharging compressed air into the high pressure unit, said low pressure stator having at its discharge end a plurality of inwardly extending support struts positioned across the air path a bearing support extending inwardly from said struts and carried thereby, and a separate bearing carried by said support in spaced relation to and in alignment with the bearing carried by the high pressure rotor, the low pressure rotor being supported in said separate bearing, attachment flanges on the adjacent ends of said high pressure stator and low pressure stator and releasable securing means holding said attachment means together.
 4. In a split compressor construction a low pressure compressor including a rotor having blades thereon and a surrounding casing having stator vanes cooperating with the blades, a high pressure compressor in alignment with the low pressure compressor and receiving compressed gas therefrom, said high pressure compressor including a rotor having blades and a surrounding casing having stator vanes therein cooperating with the blades, each of said casings having a cooperating outer sleeve projecting therefrom, said sleeves extending toward and into contact with each other and located at the outlet end of the low pressure compressor and the inlet end of the high pressure compressor respectively, releasable attachment means securing said sleeves together, each outer sleeve having supporting struts extending inwardly across the gas path and a cooperating inner sleeve at the inner ends of the struts, a bearing mounting extending inwardly from each inner sleeve and each mounting supporting a bearing therein with the bearings in alignment, the bearing carried by the high pressure sleeve supporting the adjacent end of the high pressure rotor, and the bearing carried by the low pressure sleeve supporting the adjacent end of the low pressure rotor.
 5. A split compressor construction as in claim 4 in which the low pressure rotor is hollow and has a projecting drive shaft attached thereto extending through the high pressure rotor and means accessible through the hollow rotor for disengaging the rotor from the shaft.
 6. A split compressor construction as in claim 4 in which the sleeves have cooperating attachment flanges at their adjacent ends with the flanges secured together by a releasable holding element whereby the low pressure compressor may be removed as an entity by the removal of said elements, with the rotor supported within the surrounding casing by the bearing associated with the low pressure sleeve. 